1. Field of the Invention
The present invention relates to an apparatus used in a surgical operation in cranial bones, and, more particularly, to a cerebral surgery apparatus for sucking and removing an affected part such as an intracerebral hematoma, a cerebral tumor, or the like.
2. Related Art Statement
Cerebral hemorrhage and subarachnoid hemorrhage can be cited as typical examples of cerebrovascular diseases. In recent years, stereotaxy using a CT (computer tomography) drainage method is conducted to remove an intracerebral hematoma or the like after the occurrence of an intracerebral hemorrhage, as shown in the "Journal of Brain Neurosurgery", Vol. 14, No. 2, pp. 123-133, published in February 1986.
In stereotaxy, a stereotaxic instrument is fixed to the head of a patient and is positioned in relation to an affected part in the brain by using a positioner provided in the instrument, and a treating instrument, such as a drainage tube, is inserted into the affected part, thereby allowing surgery to be conducted. In this type of sterotaxic surgery, the positioning accuracy has in recent years been improved by the use of CT in which an affected part is determined on the basis of a cross-sectional image of CT to allow positioning to be effected. Consequently, it has become possible to check at a microscopic level the intervention to which the patient is subjected.
Examples of surgical apparatuses that are used in this type of stereotaxy are disclosed in Japanese Patent Publication No. 25377/1986, Japanese Utility Model Publication No. 26088/1987, etc.
As a method of removing an intracerebral hematoma by stereotaxy, it is conventional for a method to be adopted in which a metal suction tube is inserted into the hematoma, and the hematoma is sucked and removed by a suction instrument such as a syringe. If the hematoma cannot be removed completely, a method is adopted in which an indwelling tube is left in a hematoma hole, a hematoma-resolving agent such as urokinase is injected, and the resolved hematoma is sucked and removed from the indwelling tube several hours later.
Another method has also come to be adopted in which a hematoma is broken down, sucked and removed by using an ultrasonic suction device.
Furthermore, biopsy of cerebral tumors, thermocautery, or the like using, for instance, Nd-YAG laser beams, is conducted by stereotaxy.
In the removal of a stereotaxic intracerebral hematoma using the CT drainage method, the state of suction of a hematoma cannot be observed on a real-time basis, so that a surgical operation is performed in a blind manner. Consequently, there is the risk of causing damage to a cerebral parenchyma. In addition, there are also cases where the intracerebral hematoma cannot be removed completely when undue efforts are made not to damage the cerebral parenchyma. Furthermore, since it is essential to proceed with the surgical operation while successively confirming the state in which the hematoma is being sucked so as not to cause damage to the cerebral parenchyma, the time of an operation tends to become extremely long. This means that the patient is subjected to a large scale invasion and the operator inevitably experiences considerable strain and fatigue.
In addition, the method of sucking and removing a hematoma by means of a sucking device such as a syringe involves problems in that the sucking pressure must be increased to a substantially high level due to the highly viscose nature of the hematoma, with the attendant danger of sucking the cerebral parenchyma as well due to the high sucking pressure, and in that the hematoma is liable to become clogged in the inner hole of the suction tube which can frequently cause the operation to be interrupted.
The diameter of the suction tube must be enlarged in order to render clogging with a hematoma less likely to occur, so that the degree of damage caused in the cerebral parenchyma increases by that margin.
In addition, in the hematoma resolving method, the resolution power of the hematoma resolvent is very small, and the situation is not such that this method can ever be clinically satisfactory. Hence, because of the retention of a catheter for a long period of time and the frequent administration of a resolvent, the possibility of a concurrent infectious disease is unavoidable, and the agony experienced by the patient is very great due to the retention of the catheter over a long period of time.
Furthermore, although the method that utilizes an ultrasonic suction device is very effective, there is a risk of causing damage to the cerebral parenchyma owing to the fact that the operation is conducted blind. In addition, since no device is available for fixing the ultrasonic suction device that would be capable of effecting an advancing and retracting operation, the advancing and retracting operation must be performed manually with the apparatus held by the operator's hand. Consequently, there is a danger that damage of the cerebral parenchyma will be caused inadvertently.
The above-mentioned drawbacks are not confined to the suction and removal of intracerebral hematomas, but are also commonly experienced in conventional stereotaxy, including operations on cerebral tumors.